This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. xc2xa7119 from an application for DIGITAL VIDEO CASSETTE RECORDER FOR PREVENTING PICTURE DISTORTION DURING SEARCH AND METHOD FOR PROCESSING PICTURE USING THE SAME earlier filed in the Korean Industrial Property Office on the nd of July 1997 and there duly assigned Serial No. 30653/1997.
1. Technical Field
The present invention relates to a digital video cassette recorder, and more particularly, to a digital video cassette recorder for preventing picture distortion during search, and a method for processing a picture using the same.
2. Related Art
Analog video cassette recorders adopt a consecutive recording method, but digital video cassette recorders adopt a non-consecutive recording method. Thus, the digital video cassette recorder displays a non-recognizable image, (i.e., an image signal whose image pixels are not arranged) on its screen, while image data recorded in a recording medium is searched.
The digital video cassette recorder has a search mode and a normal reproduction mode. The digital video cassette recorder cannot reproduce a picture having the quality of a normal picture in the search mode, since it scans more tracks at a time than in the normal reproduction mode. Accordingly, image data which is difficult for a human to recognize is displayed during the search mode.
The following patents are considered to be representative of the prior art, and are burdened by the disadvantages set forth herein: U.S. Pat. No. 5,583,936 to Wonfor et al. entitled Video Copy Protection Process Enhancement To Introduce horizontal And Vertical Picture Distortions, U.S. Pat. No. 5,452,096 to Ito, entitled Recording/Reproducing Apparatus Wherein The Same Frame Of A Video Signal Is Repeatedly Read Out Of A Memory To Produce Special Effects, U.S. Pat. No. 5,179,479 to Ahn, entitled Method Of High Speed Searching For A Desired Tape Portion In A Digital Audio Tape Recorder, U.S. Pat. No. 5,748,332 to Lee, entitled Video Repeat Reproduction Method And Apparatus, U.S. Pat. No. 5,233,485 to Yang, entitled Index Search Method And system Thereof For Digital Video Cassette Tape Recorder, U.S. Pat. No. 5,406,381 to Han, entitled Character-Displayed Index Search System And Method, U.S. Pat. No. 5,510,889 to Kim, entitled Method Of Multi-Speed Recording-Reproducing A Video Signal I Digital Video Cassette Recorder, U.S. Pat. No. 5,523,896 to Park, entitled Variable Speed Reproducing Apparatus For A Digital Video Cassette Recorder, U.S. Pat. No. 5,528,382 to Kato et al., entitled Reproduction Apparatus For Video Signals Accompanied By Control Information. U.S. Pat. No. 5,587,789 to Lee et al., entitled Apparatus And Method For Controlling Recording And Reproduction In Digital Video Cassette Tape Recorder, U.S. Pat. No. 5,479,265 to Kim et al., entitled Video Data Recording Apparatus For Digital Video Cassette Recorder, U.S. Pat. No. 5,418,623 to Park, entitled Method Of Recording And Reproducing A Video Signal With Improved Quality During Variable Speed Operation, and U.S. Pat. No. 5,675,693 to Kagoshima, entitled Video Signal Reproducing Apparatus With Plural Search Functions.
To solve the above problem, an object of the present invention is to provide a digital video cassette recorder which prevents picture distortion during search by scanning some frames in a normal mode and displaying the scanned frames on a screen before execution of a search operation, and by simultaneously controlling the search operation to be executed in a search mode.
It is another object of the present invention to provide a picture processing method using the technique of the above digital video cassette recorder.
To accomplish the first object, there is provided a digital video cassette recorder which includes: a search command applier; a reproduction unit for outputting data reproduced at a normal mode according to a fourth control signal; a switch for selecting reproduced data output by the reproduction unit for a predetermined time according to a first control signal; a memory for storing the image data which is reproduced in the normal mode and output from the switch; a display for displaying the image data stored in the memory according to a second control signal; a capstan motor for converting the traveling speed of a tape depending on a normal reproduction mode or search mode according to a third control signal; and a controller for outputting the fourth, first, second and third control signals for controlling the reproduction unit, the switch, the display and the capstan motor, respectively, when a search command is applied from the search command applier. The predetermined time mentioned above is the time for normally reproducing a predetermined number of frames.
To accomplish the second object, there is provided a method of processing a screen picture during search, comprising the steps of: (a) applying a search command; (b) reproducing a predetermined number of frames in a normal mode; (c) storing image data reproduced in the normal as mode; (d) executing search operation simultaneously while displaying the stored image data; (e) ad preventing reproduced data from being displayed and displaying searched data instead if desired image data is searched; and (f) determining whether display of the searched data is completed, and whether the search operation will continue. If the display of the searched data is completed and a new search is to continue in step (f), the steps (d) to (f) are repeated. Also, if the display of the searched data is completed and a new search is to continue in step (f), the steps (b) to (f) are repeated. In addition, the searching step (d) comprises the steps of: converting a traveling speed of a tape to a traveling speed used during the search; and preventing data reproduced during the search from being displayed.